Jon Lee Anderson’s 1997 biography of Che Guevara (Che Guevara: A Revolutionary Life) is a masterful chronicle of Che Guevara’s life, and for me, is the most complete English language book on him. Anderson had access to Cuban state archives for the book. If I remember correctly, during the writing of the book he was able to help locate Che’s remains in Bolivia and “re”-patriate them to Cuba. The book also has a fairly complete history of the Cuban Revolution and Che’s role in it.